The accident took place in Baniapara area of the district at 1:30pm on Friday.
Among the deceased, five were women while the rest were children, Sirajul Islam, inspector of Joypurhat Fire service and Civil Defence said.
Further details of the deceased could not be known immediately, the inspector added.
Masud, who is a part of the rescue team, told this correspondent that eight bodies have been recovered. The number of casualties might be increased.
The bus was heading towards Bogura from Joypurhat, he said.
Till filing of the report, the rescue operation is continuing.